Barcelona set Dani Alves contract D-Day as Manchester City and Chelsea lie in wait for £30m star

Exasperated Barcelona officials have set a December 31 deadline to clinch a new contract with Chelsea and Manchester City target Dani Alves.

The champions of Spain know that the January transfer window represents the last chance to get a big fee for the Brazil right back if they are unable to reach an agreement with him.

Alves is out of contract in 2012 and has been keen to sign a new deal since last year, when a raft of his team-mates were handed hefty salary increases.

Pricey: Dani Alves (right) is the world's most expensive right back, and could cost Chelsea or Manchester City a cool £30m if he moves to the Premier League

The club are reluctant to overextend themselves since new president Sandro Rosell discovered the true extent of Barca's debts, but Alves's agent won't settle for a cut-price deal.

'Dani is one of the best defenders in the world and the big clubs desire his services,' said the agent Joaquin Macanas. 'We only ask that Barca value him in reality for his work and development during these years.'

Barca would seek £30million for the former Sevilla man in January if they can't reach a compromise, which would leave Chelsea biding their time.

Roberto Mancini would be interested in adding such a quality right back to his Eastlands staff, but City don't want to be seen as an easy touch in negotiations.